Cone-type drill bits have been successfully employed in forming boreholes into the ground. Cone-type bits are especially useful in air drilling operations, where the borehole extends through frozen formations, as for example, the perma-frost found in the Artic region. Sometimes it is beneficial to vibrate the cone-type bit as it is rotated, thereby enhancing the drilling action.
Cone-type bits of the prior art sometimes lose their efficiency because the formation engaging surface of the bit becomes clogged with debris, and at other times oversized cuttings tend to obstruct the outlet passageway leading from the bit.
Accordingly, it is desirable to provide a cone-type bit having a formation engaging surface thereon which utilizes the rotary energy imparted into the bit in a more efficient manner. Moreover, it is desirable that such a bit have arranged thereon a cutting face which engages the formation in a manner which precludes oversized cuttings being formed. Furthermore, it is desirable that such a bit be low in cost, easily repaired and maintained, and efficient in operation.